Gas-impervious container



July 6,1926. 1,591,432

P. O. NOBLE GAS IMPERVIQUS CONTAINER Fil 'ed May 5, 1922 l Y /Z -2 m 4 HQ 5 g POIFES SEALED l J I 1 ii. an

Inventor: Paul O. noble,-

: the cover 3 is drawn andby the use of a sealing li uid 8, such as by Letters Patent of, the'Umted States,-1s:

Patented July 6, 1926.

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CQIPANY, A- CORPORATION OF NEW YORK.

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Application flea lay i, 1922; Serial 1w. 158,658.

In accordance with my present invention I have rovided a metal container, the walls of whic are so imperviousto gas that a' high vacuum may be maintained therein indefil nitely. y

Heretofore, evacuated containers. of metal have required during the operation intermittent or continuous pumping to prevent a undue deterioration of the vacuum. Even when leakage through the seals was pre- -cluded,the vacuum deteriorated apparently by slow leakage of as through extremely,

The pores, or crevices in the metal are so minute that various ordinary coatings of enamel or minute crevices. in t e metal walls.

the like applied on the surface had no material effect on the porosity. Apparently the vviscosity of ordinary coating materials is too great to permit'their penetration into crevlces as minute as those present in a metal I such as steel.-

y In accordance with my provided a containerrendered so im ervious to gas by a metal 'sealingmr filling t e ores that a high vacuum may e maintained t erein without substantial deterioration.

The new gas-tight devices embodying my invention are the. result of my discovery, that in a reducing atmosphere the penetrability or fluidity of certain metals, particularly copper and silver, is so extraordinary that these metals will enter openin of microscpipic dimensionsin metal wette thereby and e ectually seal the same. Containers embodying my invention-are suited to various industrial applications, for example, for

evacuated highpowered mercury arc recti- .fiers. f-v

- The accompanying drawing shows one em- I bodiment oi my invention, namely, a metal tank mercury arc" rectifier.

The. rectifier here shown comprises a tank preferably of steeL. To the uppernm 1s omed a channeled flange 2;'con-- u jvenientlyby electric Welding; The cover 3 has projecting a. circularnb 4 extending into the channel ligand bearing a inst a gasket 6 consi of asbestos or ot er suitable material. y tightening the bolts 7 "'mercury, a-gas-tight sealis ma e. The anode stem 9 is s milarly'sealed against an insu- I later '10.- When the bolts '11 are drawnv be ,d w against theplatem, the mercury sealed invention, I'haveby the fiui metal. The

1 penetrating microscopic own upon the gasket gaskets 13, 14 are made gas-tight. .The container 1 contains a mercury cathode 15 from which an arc'is producedto an anode 16 in any well known manner. I j 1 In carrying out my invention the tank 1, 00

cover 3 and other parts to be assembled as acontainer are coatedeither externally. or internally, or both, with copper in any suitable manner, conveniently by 'electroplatm or by spraying with finely divided meta.

" The thickness of the metal to be rendered gas-tight may vary considerably, but, the coating-ordinaril need be only a few mils in thickness. A though various cupreous metals, suchas alloys of copper can be used or even silver, I prefer to use copper andI prefer to a ply the same on the external surface of t e container."- The coated pa'rts are heated to the melting oint of the copper "or other sealing metal m h drogen, carll bonmonoxide or other 'suita le reducin gas, thereb causing the pores to be fill process of joining metals to each other by" e use, of copper,

or the like, fused in, a hydro en or other. reducing atmosphere, is descri in Cooliclge Patent 1,181,741. The adaptability o'f the fluid metals underthese conditions for pores leadin into the body of steel or slmilar metal in t e reducing atmosphere heretofore has not been utilized.

Machinin shows that in some cases the 'fluid coppgr v penetrates a considerable'depth'in the y 00 of the iron or steel. Test pieces have shown a' penetration through minute pores for d1stances as great as 7 inch. -.Gontaine rs prepared from. copper-sealed steel in accord.- ance with my nvention have held a high OI vacuum for rotracted periods without appreciable 10 age.

Although I have described my mvent1on, withpartlcular reference to evacuated mercury are devices, I wish it to-be understood that the advantages of *my invention are not limited to evacuatedcontainersbut that any containers which are to be in a 'gas-, tightcondition can toadvantage embody myinvention. f ,'1N

" What I claim as new 'and-desire'to secure 7 of sheet metal thus treated 1. In combination, an electrical device comprising a ferrous metal container, thev outer surface of said eontainerbeing' imprcg-i DO nated with a metal adapted to seal the pores of the container and render it gas-eight, and means whereby a metal vapor arc may be operated in said device.

2. An electrical discharge device comprising a container of ferrous metal, one of the surfaces of the container being impregnated with cupreous metal to thereby seal the pores of the container, and means for operating a metal'vapor arc therein.

3. In combination, an electrical device.

comprising an evacuated ferrous metal contalner, means for sealing the pores of sald container to render the contalner gas-tight 

